Overload indicator for measuring instruments



oct. 22, 19 29; c, MULLEN 1,732,338

OVERLOAD INDICATOR FOR MEASURING INSTRUMENTS Fild Oct. 24', 1928 v 2Sheets-Sheet 1 @H'oznmp Oct. 22, 1929. c. A. MULLEN OVERLOAD INDICATORFOR MEASURING INSTRUMENTS Filed Oct. 24, 1928 2 Sheets-Sheet 2 avwcmhwC. u9.M u Z Zen atto'cwwo Patented Oct. 22, 1929 PATENT OFFICE CLYDEA.-MULLEN, F ASBURY PARK, NEW JERSEY OVERLOAD INDICATOR FOR MEASURINGINSTRUMENTS Application filed October 24, 1928. Serial No. 314,779.

The present invention is directed to improvements in overload indicatorsfor measuring instruments.

The primary object of the invention is to provide a device ofthischaracter especially designed for use in connection with switch boardinstruments, such as ainmeters and wattmeters, or the like, theconstruction being such that when the pointer is shifted to a positionbeyond full scale, a target will be actuated to indicate that thepointer has been moved beyond the full scale position.

Another object of the invention is to provide novel means for resettingthe target, the

, constructionbeing readily accessible and will in no way interfere withthe working parts of the instrument.

Another object of the invention is to provide a device of this characterwhich is simple in construction, and can be installed upon instrumentsalready in use.

With these and other objects in view, this invention resides in thenovel features of construction, formation, combination and arrangementof parts to be hereinafter more fully described, claimed and illustratedin the accompanying drawings, in which Figure 1 is a front view of aninstrument showing the device in place thereon.

Figure 2 is a sectional view with parts broken away.

Figure 3 is a front view of the indicator, showing the relativearrangement of the frame and resetting arm.

Figure A is a sectional view on line 4-4; of Figure 6.

Figure 5 is a longitudinal sectional view through the frame showing thetarget in its operative position.

Figure 6 is a sectional view on line 66 of Figure 4.

Figure 7 of Figure 1.

Referring to the drawing, 1 designates the instrument which may be ofany well known is a sectional view on line 77 type and includes theusual dial 2 having a scale thereon and a pointer 8 adapted to travelover the scale.

Suitably fixed to the dial 2 .is a back plate a of a frame 5, said platehaving an end plate 6 which supports the front plate 7 in spacedrelation with respect thereto, the latter plate having an enlarged plate8 carried thereby and in which is formed a sight opening 9, the purposeof which will be later explained.

Journaled between the plates 6 and 7 is a shaft 10, said shaft havingfixed thereto an arm 11, the upper end of which carries a target 12colored white.

The lower end of the arm 11 extends slightly below the frame 5, thepurpose of which will later appear. Also fixed to the shaft is a triparm 18 the upper end of which is provided with a projection 14 which islocated in the path of movement of the pointer 3. It will thus be seenthat when the pointer moves to an overload position that the projection14 will be engaged whereby the shaft 10 will be rocked to move thetarget 12 from its normal position into registration with the opening 9.

In order to reset the target it is necessary that the arm 11 be rockedin a counter clockwise direction, and in order to accomplish this thelens 15 of the instrument is drilled to provide an opening 16 in whichis fitted a sleeve 17 and journaled in said sleeve is a shaft 18.

The sleeve 17 is retained in the opening by clamping nuts 19-19, andinterposed between the nuts and faces of the lens are packing washers20-20.

The outer end of the shaft 18 carries a turning knob 21 while the innerend has fixed thereto an arm 22 having a lateral extension 23 upon itsupper end which is adapted to engage the lower end of the arm 11 toswing the same in order that the target 12 will swing out ofregistration with the opening 9.

A coil spring 24 encircles the inner ends of the sleeve '17 and has oneend fixed to the inner nut 19, while the other end thereof terminates ina finger 25 adapted to yieldably bear against the arm 22 so as to holdthe same against the pin 26 carried by the inner nut, said pin obviouslylimiting the swinging movement of the arm 22 in one direction.

It will be apparent that when the pointer 3 moves to the extreme rightit will strike the projection 1 f thereby rocking the arm 11 to theposition as shown in Figure 5 and at which time the target 12 willcoincide with the opening 9 to indicate that an overload has occurred inthe circuit. To reset the target the knob 21 is turned clockwise inorder to swing the arm 22 to cause the finger 23 to engage the lower endof the arm 11 to swing the same to a position as shown in 0e 4 and atwhich time the target is concealed by the plate 8. When the shaft 17 isrotated clockwise the spring 24 will contract and upon releasing theknob expansive action of the spring will rotate the shaft anti-cloclewise to swing the arm 22 to its normal or inoperative position, thereverse swinging movement of the arm being limited by the pin 26.

If desired an alarm may be'incorporated in the circuit and will 01 crateto indicate that the arm has been swung to full line position of thescale. 2

From the foregoing, it is thought that the construction, operation andmany advent of the herein described ention will. b i parent to thoseskilled in the art, without further description, and it will be understood that various changes in the size, shape, and proportion and minordetails of construction, may be resc'ted to without dep rting from thespirit or sacrificing any of the advantages of the invention.

What is claimed is 1. The combination with the pivotally mounted pointerof a measuring instrument, of a target associated therewith, a platehaving a sight opening therein, and means operable by the pointer whenswung in one direction for shifting the target in direct registrationwith the sight opening.

2. The combination with the pointer of a measuring instrument, of aframe having a sight opening therein, a shaft rotatabiy supported by theframe, an arm fixed to the shaft and having a target upon its upper end,and a trip arm carried by the shaft for engagement with the pointer whenmoved in one direction to rock the shaft tov move the target intoregistration with said open ing.

f 3. The combination with the pointer of a measuring instrument, of aframe having a sight opening therein, a shaft rotatabiy sup ported bythe frame, an arm fixed to the shaft and having a target upon one end,means carried by the shaft for actuation by the pointer when moved inone direction to rock the shaft to move the target into registrationwith the said opening, and manually operable means rotatably supportedby the instrument forengaging the arm to rock the same to move thetarget from registration with said opening.

4. The combination with the pointer of a measuring instrument, of aframe carried by the instrument and having a sight open ing therein, ashaft rotatable in the frame, an arm fixed to the shaft and having atarget upon its upper end, a trip arm fixed to the shaft, and meanscarried by the trip arm for engagement with the pointer to rock theshaft to move the target into registration with said opening.

5. The combination with the pointer of a measuring instrument, of aframe carried by the instrument, said frame having a sight openingformed therein, a shaft journaled in the frame and having an arm fixedthereto, a target carried by the arm, a trip arm fixed to said shaft andhaving a projection upon its upper end in the path of movement of thepointer, said projection being engageablewith the pointer when thepointer is moved in one direction to rock the trip arm and thusthe shaftto move the target into registratiou with the sight opening. I

6. The combination with the pointer of a n ensuring instrument, of aframe carried by the instrument and having a sight opening formedtherein, a shaft journaled in the frame and having an arm fixed thereto,a target carried by the upper end of the arm. a trip arm fixed to saidshaft and having a projection upon its upper end, said projection beingadapted to be engaged by the pointer when said pointer is moved in onedirection, whereby the trip arm rocks the shaft to move the target intoregistration with the ai it opening, a shaft rotatably supported by theinstrument and having an arm fixed thereto for engagement with. thefirst named arm to rock the same in a direction to move the target fromregistration with the sight opening.

7. The combination with the pointer of a measuring instrument, of aframe carried by the instrument and having a sight opening formedtherein, an arm pivotally supported by the frame, and having target uponone end, means operable by the pointer for rocking the arm for movingthe target intoregistration with the opening when the pointer moves inone direction, a shaft carried by the instrument and having an armcarried thereby for engagement with the first named arm to swing thesame in the reverse direction to move'the target from registration withthe opening, and yieldable means for returning the last named arm in itsinoperative position.

In testimony whereof I my signature.

CLYDE A. MULLEN. '[n q

